<p>The game goes like this</p>
<p>The first person (ALA me) will post a single movie</p>
<ol>
<li>The Dark Knight</li>
</ol>
<p>If you have seen it add it to your list. The number of movies that you have seen on the above person's list is the number of movies you can add to your own list</p>
<p>Since the second poster has seen the dark knight, he can add one movie to his list</p>
<ol>
<li>The Dark Knight</li>
<li>Avatar</li>
</ol>
<p>The third poster has seen the Dark Knight, But not avatar. So he has to subtract one movie from his list. Which brings him back to 1 (you can never hit 0)</p>
<ol>
<li>Shawshank Redemption</li>
</ol>
<p>So on and so on, now the 9th poster's list is this</p>
<ol>
<li>Shawshank</li>
<li>Avatar</li>
<li>Coraline</li>
<li>Toy story 3</li>
<li>Jurassic Park</li>
</ol>
<p>The 10th poster has only seen 3 of those films. So he subtracts 2 from his list Which means 3-2 = 1.</p>
<p>Try to make a big list!</p>